Pulse counting and registering circuits



Dec. 23, 1952 F. K. Low 2,623,114

PULSE COUNTING AND REGISTERVING CIRCUITS A T7' ORNE V l F. K. Low

PULSE: CQUNTING AND REGISTERING CIRCUITS Dec. Z3, 1952 Filed Jan. '7, 1950 /NVENTOR By l EK. 0W

ATTORNEY N .gl

Dec. 23, 1952 F. K. Low

PULS COUNTING AND REGISTERING CIRCUITS 4 Sheets-Sheet 5 Filed Jan. '7, 1950 mmm NDT(

/NVEA/roR E K. LOW 6". 6. min- ATTORNEY Dec. 23, 1952 F. K. Low

PULSE couNTING AND REGISTERING CIRCUITS Filed Jan. 7, 1950 4 Sheets-Sheet 4 /NVENTOR E K. LOW

A TTORNEY Patented Dec. 23, 1952 UNITED STATES TENT OFFICE PULSE COUNTIN G AND REGISTERING CIRCUITS Application January 7, 1950, Serial No. 137,323

Claims.

The present invention relates generally to signaling and registering systems and to relay circuits thereof and more particularly to relay circuits of the counting and registering type.

In the telephone switching art there are numerous applications of relay circuits for counting and registering information such as digits and pulses of a digit. The present invention finds utility in such applications, in addition to others which will be suggested to those skilled in the art of relay circuits.

For a number of reasons, which will be apparent in subsequent description of a preferred embodiment of the invention, the characteristics of enclosed magnetic reed type switching elements, having only make contacts, make such elements particularly desirable as means whereby inexpensive, simple, rapidly responsive counting and registering circuits may be arranged. Such elements comprise at least two normally separated contact elements which are enclosed in an envelope which is in turn enclosed partly or wholly within an energizing coil, whereby upon the energization of the coil at least one contact element will move to make contact with the other element under the influence of the magnetic eld set up by the coil and by any polarizing inuence which may be used if desired. Such relays include sealed contacts among their advantages.

As a result of the problem presented of devising counting and registering circuits using relays having only make contacts, the present invention provides such circuit arrangements which permit the use of such magnetic reed relays as the preferred means to an end. However. as will be appreciated by those skilled in the art, any relays of which only the front or make contacts are used, may also serve as such means. Furthermore, the present invention is not limited to applications where only front or make contacts are used for it is entirely probable that those skilled in the art as a result of this disclosure will infer therefrom similar arrangements which use back contacts of relays as well as front or make contacts without going beyond the scope and spirit of the present invention.

As an exemplary disclosure of the present invention the subsequent detailed description and drawings describe and show preferred embodiments of the invention as used in a telephone system such as disclosed in Patent 2,585,904 to A. J. Busch of February 19, 1952, and in Patent 2,616,- 974 to J. W. Dehn of November 4, 1952. These systems are cross bar automatic systems which use originating register circuits, which are com- 2 mon to calling lines and which are used for transmitting the usual dial tone to a calling subscriber and for receiving, counting, and registering the called number digits dialed by such subscriber.

The drawings comprising a part of this disclosure show a skeletonized originating register circuit the various portions of which may be described generally as follows:

Fig. l shows part of the originating register termination of a calling subscribers line, the relay L( l) oi the register which follows line pulses. off-normal relay ONU), etc.;

Fig. 2 shows a chain of relays arranged for counting the impulses in each digit;

Fig. 4 shows a group of register relays for registering on a two-out-of-five basis as many as eight digits;

Fig. 3 shows a group of steering relays for insuring that successive digits are registered in successive register relay sets, such as the A register, the B register, etc. of Fig. 4; and,

Fig. 5 shows how the other figures may be arranged to disclose the invention.

One form of the present invention is embodied in the HX code prefix detecting and registering circuit in theupper right portion of Fig. l, in the counting relay circuit of Fig. 2, and in the steering relay circuit of Fig. 3.

The invention, in one of its aspects, provides a chain circuit arrangement of relays actuated and controlled by a pulsing conductor upon which impulses are applied from a source of current, each of said relays being arranged in circuits for accomplishing the following functions when operated by an impulse over said pulsing conductor:

(l) Each counting relay when operated is arranged to lock under its own control to a ground common to all;

(2) Each counting relay includes contact means arranged upon the operation of said counting relay to connect the next succeeding relay to said pulsing conductor preparatory to the operation of said next succeeding relay by the next pulse on said conductor;

(3) Each counting relay includes contact means arranged upon the operation of such counting relay to prepare a shunt circuit for the next preceding relay, which shunt is completed by suitable means at the end of the pulse; and,

(4) Each counting relay includes contact means arranged upon the operation of said counting relay to prepare a shunt circuit for the second succeeding relay to prevent the operation 3 of said second succeeding relay while such counting relay is operated.

The invention further provides means for completing the shunt circuit across said next preceding relay at the end of the pulse, thereby to release said next preceding relay.

The invention provides, as above outlined, relay circuit means for successively operating one relay at a time along the circuit as an indication of the accumulated count of pulses.

The present disclosure shows a registering relay circuit Wherein relays having only make or front contacts may be used. Each register relay has one side of its winding connected through a current limiting impedance to a nrst source of potential of one magnitude, such as a. direct current voltage, and the other side of its Winding connected through another such impedance to a second source of potential of another magnitude, such as ground. Each digit register comprises a plurality of individual relays which are operated on a code combination basis to represent a particular digit, such as a two-out-of-iive code where ve such relays represent each digit register group. All the relays of a group have their other winding sides connected in the above fashion to the same second source. Each of the first, second, third, etc. relays of all groups have their one winding sides connected to the same first-first source, second-first source, third-first source, etc. in the above fashion. Thus at all times when such register relays are in use each relay winding carries a current limited by the two impedances in series therewith. This current is of a magnitude which is not sufficient to operate a relay but is sufcient to hold a relay operated once it has been operated. This current is designated the holding current. Means is provided for momentarily applying said second source of potential, say ground, directly to the other side of all relays of a particular group and for momentarily applying said rst source of potential, ysay battery, directly to the one side of a combination of first, second, third, etc. relays of all groups. The result isthat only that combination of relays will be operated which have applied directly to their windings both sources of potential thereby to increase the current flowing through such windings to the operate" value. All other relays will carry increased current due to the' application to one side or the other, but not both, of their windings the respective sources of potential. These latter relays will carry a current greater than the holding value but less than the operate value and will not operate. At the end of the momentary selective application of said potential all relays will revert to a condition whereunder they carry only holding current, which, of course, retains operated only that combination of relays of a group which were operated as above outlined.

The above described registering circuit is disclosed and claimed in application Serial No. 271,911, filed by F. K. Low on February 16, 19/52, which application is a true division of the present application.

The principles of the invention will be understood best from the subsequent detailed description of preferred embodiments thereof.

GENERAL DESCRIPTION embodied in an originating register 'circuit ofjaj -cross-bar system of the type disclosed in' detail in Patent 2,285,904 to A. J. Busch of February 19, 1952. The present disclosure concerns only certain portions of such an originating register, which portions are disclosed in Patent 2,616,974 to J. W. Dehn of November 4, 1952. The Dehn disclosure is considerably simplified and sl-:eletonized, as compared to the complete Busch disclosure, and will afford sufficient information upon which one skilled in the art may rely to appreciate the advantages of the present invention as embodied, by example, in such systems.

A general description of some of the functions of an originating register circuit as employed by Busch or Dehn is considered desirable before going into the details of an exemplary disclosure of the present invention. When a calling subscriber initiates a call, common control equipment, termed a marker, is brought into service to interconnect such subscriber with an originating register circuit. This register circuit is arranged to provide the usual dial ton-e signal to the -subscriber as a directive to commence the dialing of the called number. As the subscriber dials the digit or digits indicative of the desired interconnection the register is arranged to count the pulses in each separate digit, to register each digit separately, and, at the proper time depending upon the type of call indicated by such digit or digits, to seize an idle marker circuit to which the called digit or digits are transferred along with other information required by such marker in performing the switching functions required to eifect the desired connection. When the marker has received all of the information registered in the originating register, the marker releases the register circuit to normal and proceeds with subsequent functions of no particular importance in understanding the present invention.

The following detailed description, including the above-described drawings forming a part thereof,is confined to the digit counting, digit steering, and digit registering operations performed by the originating-register prior to the seizure of .anidle markerfor the purpose of completing-'thedesired connection. All circuit operations prior to the seizure of an idle originating register and just prior to the seizure by the register of an idle marker have been omitted as unnecessary, the above Busch and Dehn disclosures providing complete details not shown or described herein.

It has been 4mentioned above that the present invention -permits the useat strategic points in the originating register'circuit of relays which have-only makejcontacts; and, whereas it is to bev understood that the present-invention is not limited to any specifictype or types of such relays, nevertheless Vthe preferred types of such relays are'4 those 'disclosed `in Patents 2,187,115 to WrB. Ellwoodand W. H. T. Holden of January 16,1940, and-2,289,830 to W. B. Ellwood of July 14, 1942; These latter types of relays are sealed magnetic reed type relays. Where only one pair ofmake contacts is required, two magnetic reeds are enclosed in an evacuated-glass envelope which is in'turn enclosed vin an energizing coil. If a plurality of make pairs *are required, several suchsingleunits mayfbe enclosed in a single coil, etc. These reed type relays are preferred for 'use V"according to the present inventionbe- ".,cause of Ytheir desirable characteristics such as sealed contacts, fast response (approaching that of gas. tubes) ,and relatively low cost. The speeld of response. both' as to 'operation and'release, of

these reed typev relays, as lwill be appreciated, will afford; among other advantages, the possibility of realizing much higher dial speeds than would be possible with-conventional general purpose relays. It is to be repeated, however, that the present invention i'sin" no way limited to any spe'cic type or types of relays.

f DESCRIPTION Seizure. ko1 originating register v Upon theseizureof an idle originating lregister byl a.- inarker circuitfthe; oi-normalrelay ON(I) in the originating. register` is operated. Relay QNII), upon operating, completes; a circuit from ground, over its. contact 4, andlconductor I to thedigit register relayy network in Fig. 4. It will be.. seeny from. an inspection of .Y the arrangement shown. infFig. 4,; that at .this-time parallel circuits. are completed for; permitting. current to ow through thewindingsofall-of the register relaysV MM45) throughH'ltl-)tinclusive. Ground on conductor-l is appliedvthroughv resistance R2I() toltheleft sideof the windings of the A digit register relaysAM) to A-l-(A). Ground on conductor |00 isf-likewise` supplied to the. windings. of the B, C, D, F, G ande digit registers throughl respectiveresistances R220!) through H2804).` The righ-t. sides of the windings of relays-AIJ(.4)B|I(II).,VV C0(4),etc. and HBM) are supplied by battery through resistance R35 (4) Likewise, relays AI(4)` through HIM) are supplied .by battery through. resistance-.RSMdL etc. The various resistances, windings, and voltages arev arranged such that there, is insufficient current-ilowingin anyl winding to operate the associated register relay. This. current will be referred to hereinafter as the holding current.

Relay ONU), upon" operating, operates. the

start relay ST(2)v in thev pulse counting circuit of Fig, 2'- in.a circuit-extending from. ground, overcontact 2of relay0N(I).,contact 5 of the slow-releasing relayV SRU), conductor lili, through--the windingotrelay` ST(2), to battery through resistance `RII(2). Relay STG) operates andilocksfover its contact. 2, conductor 200,; to ground. over-Contact zv of relay ONM). The,-relay.,ST(2) is the start relay ofthe pulse counting 'chain shown., Fig. 2 as comprising relays-PI (2) to PL|1`(2) inaddition-to relayST(2). Relay AS'l(2) is operated and locked, asv above, to prepare thecountng chainffor the yreception of the first pulse ofthefirst digitto Vbe dialed by thecalling subscriber.

. 1.elayrONf(.I),Vv upon. operatingr operates relay IIA(I).. in afcircuit extending from ground, over contact 2 of. relay.V ONU), contact 2 of relay SR( 'I.),windingy of relay` HAU), to battery through resistance. VR.I2(I).. Relay IIA(I) operates-and locks over its. contact.2, toground over contactl.- of relay ONU). Relay IIA(I) is operated ini-order' to condition the group of relays I IA(.I)', II.B(I,).,.andl IX(.I') preparatory t0 the recognition -of a. single yinitial pulse, which will be absorbed,1 or. of two initial digits of the Value of one pulseeach,y which will indicatev that the called, number involves a 1`1X` toll directing prefix or speciallservice code where X may be any'digitjfron'i 2` to 9.

Relay ON"(I), Vupon operating, operates the steering' relay ASG) associated with the register iff-:laysv ADCI) to A1(4), in' a circuit extending from ground, over contact. I of. relay ON( I), contact I of relay SRU). conductor |02', winding oi' Cil relay AS(3), to battery through the resistance Rftl(3). Relay AS(3) operates yandloclrs over its contact 2, conductor 300, to ground over contact l of relay ONU). Relay ASG), upon operating, prepares the register relay network of Fig. 4 for registration of the rst digit (unless-it be a digit 1 re above) in theA digitre'gister relays ABM) to Alot).

Preparation of originating register for counting digits Subsequent tot he seizure by a. marker ofthe originating register and the operation of the oifnorrnal relay ON (I) therein with theresultsef'- fected thereby, as above described, the marker will effect the necessary switching operations to interconnect the calling subscrbers line circuit with the seized originating register, whereupon` the marker. will release. The details ofi-such switching functions may be obtained irom the above Brusch disclosure. Upon the completion of. such interconnection a circuit is completed.v for operating the relay LH) from battery, through the upper winding of relay L(I), through the lower left winding of the dial tone transformer 95, over the ring conductor EN of the` trunk link frame switch terminating the originating register, through the switch train to thevv ring conductor of the calling line, over the closed iine loop, back over the tip conductorof the calling line, through the switch train, over the tip conductor Iii?, of the trunk link frame switch, through the upper left winding of the dial tone transformer H35, to ground. RelayLU) operates in the above-traced circuit.

Relay L(i), upon operating, moves its armature from the normal released position thereof, as shown in contact with contacts 3 and 4 of relay L( i to the operated position thereof in contact with contacts I and 2 of relay L(I). Relay SR( E) is thereupon operated in a circuit extending from ground, over Contact 3 of relay ON( I armature and contact I of relayA L(I), through the lower low resistance winding of relay L( I to battery through the winding of relay SRU).

At this point relays ON(I),L(I),.SR( I ST(2) i IAG), and AS(3) are operated, the latter threel relays remaining operated under the control of the ofi-normal relay ONU) upon the above-dar scribed operation ci relay SR( i [i dial tone signal is supplied to the calling subscriber from the source II2 thereof through the right primary winding of the dial tone transformer it, by induction into the upper and loweil left secondary windings of transformer E55, and over the subscribers line by way of the switch train. The subscriber may now dial the digitsy of the called number.

Ahsmbing initial of one pulse it is well known that when a subscriber dials, the mechanism at his substation produces a momentary open condition in the line loop iollowed by a closure thereof for each pulse of each digit and that the line closures between pulsesA of a digit are much shorter in duration than the closures thereof between digits.

If by accident, or otherwise, an initial digit ci one pulse is transmitted, the originating register is arranged to absorb this pulse onthe as sumption that it is transmitted or created in error. The circuit is arranged, however', as previously indicated, to recognize a iirst digit of one pulse followed by a second digit 'of one puise as a legitimate indication that aspecial 11X code is to be transmitted, and prepares itself to register successive digits.

The structure of the relay L(I) is preferably, but not necessarily, of the mercury contact type similar to the structure of the mercury contact relay disclosed in Patent 2,577,602 to E. T. Burton of December 4, 1951. The armature of relay L( I) is biased towards its contacts 3 and 4 as has been mentioned. This bias, as in the type of relay disclosed by Burton, may be both partly mechanical due to the usual spring and partly magnetic due to the presence of a permanent magnet, if desired, influencing contacts 3 and 4. When relay L(I) is operated, under closed loop conditions, the current flow through the lower winding in series with relay SR/(I) is arranged to counteract partly the effect of the current flowing through the upper winding. This, in eiiect, increases the total bias tending to release the armature when relay L( I) is operated. This is to improve tlie releasing response of relay L( I thereby aiding its performance under line conditions which tend to retard the release of relay L(I). The purpose of the middle winding in series with condenser C2(I) is well known to provide a measure of pulse correction action, as described for instance in Patent 2,029,723 to L. H. Johnson and F. K. Low of February 4, 1936.

Upon the release of relay L( I during the first open loop period of the first digit, relay RAM) is operated in a circuit extending from ground, over contact 3 of relay ON(I), armature of relay L(I), Contact 3 of relay L(I), contact 3 of relay SRU), to battery through the winding of relay RA( I) Relay RA( I upon operating, completes, at its contact 2, an obvious circuit for discharging any charge which may have been accumulated on condenser C3(I), the importance of which function will be evident from subsequent description. The operating ground for relay RA(I grounds the left side of the unidirectional current carrying element V(I), which is arranged in the circuit to represent a low impedance shunt across the winding of relay RA( I) when the ground is removed, thereby retarding the release of relay RA(I). Relay RA(I) remains operated during the interval between pulses of a digit; but, relay RA(I) will release during the interdigital period. Relay SRU) remains operated, due to its slow-release characteristic, during open loop periods when relay L(I) is released.

Relay L(I), upon releasing, operates the rst counting relay PI (2) in a circuit extending from ground, over contact 3 of relay ONU), armature of relay L(I), contact 'I of relay L(I), contact 4 of relay SRM), conductor IDG, contact I of relay ST(2) winding of relay PI (2) to battery through the resistance RI (2). Relay PI (2) operates and locks over its contact 2, conductor 23d, contact 5 of relay RAI(I), to ground over contact 2 of relay ON( I When relay PI (2) operates at this time, the fcllowing functions are performed:

(l) The operating ground for relay PI 2) conductor IGS is extended over contact I of relay PI(2) to the left side of the winding of relay P2(2), relay P2(2) not being able to operate because the right side of its winding is shunted to ground over contact 3 of relay ST( 2) (2) Contact 3 of relay PI (2) is closed to partly establish a shunting ground circuit (which will be completed when relay L(I) reoperates at the end of the pulse from the armature of relay L( I), contact 2 of relay L(I), conductor It?, contact 3 of relay PI (2), to the right side of the winding 8 of relay ST(2)) for releasing relay ST(2) by shunting it down when relay L(I) reoperates; and,

(3) Contact 4 of relay PI (2) is closed to extend ground to the right side of the winding of relay P3(2), thereby to prevent the operation of relay P3(2) when and if relay P2(2) operates during a second pulse.

When relay L(I) reoperates, upon the closure of the line loop at the end of the rst pulse, relay SR( I) i-s reenergized and the operating circuit for relay RA(I) is opened, relay RA(I) remaining operated under the control of element V(I) as above described. Relay L(I), upon reoperating, extends ground over its contact 2, conductor IIlI, contact 3 of relay PI (2), to the right side of the winding of relay ST(2), thereby shunt releasing relay ST(2). Relay ST(2), upon releasing, removes, at its contact 3, the above-mentioned ground from the right side of the winding of relay P2(2), thereby permitting relay P2(2) to operate upon the next release of relay L(I),if any, representing a second pulse of the first digit.

Since it has been assumed that the rst digit contains one pulse, relay L(I) will remain operated long enough to permit relay RA( I) to release. Relay RA(I), upon releasing, connects the discharged condenser C3( I) in series, over contact I of relay RA( I with battery through the winding of relay RAI (I). Relay RAI (I) will be operated by the transient charging current and will release when the charging current has been reduced below the releasing current value for relay RAI(I), even though relay RA(I) may remain released.

Relay RAI(I), while operated, releases relay PI(2) by removing ground from conductor 20| and reoperates relay ST(2) by applying ground to conductor IUI over contact 6 of relay RAMI). Relay ST(2) as before, locks to off-normal ground on conductor 200. Relay RAI I while operated, completes a circuit for operating relay IIB(I) from ground, over contact I of relay RAI(I), contact I of relay P2A(I), contact I of relay IIA(I), to battery through the winding of relay IIB(I). Relay IIB(I) operates and locks over its contact 2, to off-normal ground over contact 2 of relay ON( I). The operating ground for relay I IB(I) is extended over contact I of relay I IB(I) to the left side of the winding of relay I IX(|) but the latter relay cannot operate because the right side of its winding is shunted to ground over contact 3 of relayl IA( I).

When relay RAI(I) releases, relay IIA(I) is shunt-released by ground, over contact 2 of relay RAI(I), contact 3 of relay P2A(I), contact 3 of relay I IBG), to the right side of the winding of relay IIA(I). Relay IIA(I), upon releasing. removes at it-s contact 3 the shunting ground on the right side of the winding of relay IIX(I) so that the latter may operate if the second digit is also composed of only one pulse. During the interval following the release of relay RA(I) and ending with the subsequent operation of relay RAI (I), ground is applied over contact 4 of relay RA(I), contact 4 of'relay RAI (I), conductor |09, contact 4 ofrelay AS(3), conductor 30| to the left sides of the windings of relays AU (4) to A'I(4). While this ground increases the current owing in their windings, such current is not increased to the operate value for such relays and none of their relays operate. Thus itwill be appreciated that the counting of the digit 1 as an initial digit has not affected the digit registersof Fig. 4 and has in fact been absorbed.

If thesecond digit is also merely composed .of one pulse,this is assumed not to be an'accident but is assumed `to be the second of' two'initiall digits preceding a third digit of from 2 to 9 which is alegitimate called code; Upon the release ofl relay vL(I), in response tothe first openloop period of the second digit, relaysRA( I) and PI (2) are reoperated asbefore. When relay 'RA(I) reoperates it dischargesv condenser C(I).' When relay L( I) reoperates, at the end `rof the pulse relay ST(2) is again released. If, as assumed, relay L(I) remains reoperated `for a'v length of time indicative of an interdigital pause, relay vRAM)v again releases to reoperate momentarily relay RAI (I) as above described. Relay RAI (I), upon reoperating momentarily, lagain' 'releases' relay PI(2), reoperates and Vlocks relay. ST(2), and operates relay. .I IX( I.) in a circuit extending from ground, over contactl .of relay RAI`(`I), contact' When relay RAI (I) releases Athe circuits will 'l' be prepared toreceive the-X digit of 2 to 9 which will be handled by. thecounting and. registering circuits as though it. were an initial digit. As will be shown hereinafter, when adigit of two pulses or greater is counted; relay PZA( l) will be operated andlocked to off-.normal ground thereby disabling', at its contacts vI and. 3, lthe abovedescribed initial one-pulse digit absorption and 11X features.

Counting, steering and registering .first digit (exclusivev .of o, 1 or 11 prefix).

It willberecalled that. when relay L.(I) reoperated at theendof the first puls of the rst digit, relays` RAM), L(I), SRU), PI(2), and HAU) were operated..

It will be assumed that the first digit, exclusive ci a 1 or a 11. preiix, is Aone containing two pulses and that therefore` the second `pulse will be received by relay L(I) beiore.relay.RA(.I) canrelease.

When' relay L(,I.) releases inresponse tothe secs ond open loop period of the second. pulse, relay RAM) is .reenergized asv before to insure. its remaining operated. Relay LH), upon releasing, operates counting relay vP2 (2) in a circuit extending from ground, `over contact 3 of relay ONU), armature of relay L(I contact 4 of r'relay L(.I), contact 4 of relay SRU), pulsing conductor |06, Contact I of relay P I( 2) winding' of relay P2 (2) to Y battery through the resistance R2 2) Relay P2 (2) operates and locks over its contact 2, conduc-tor20 I, contact 5 of relay RAI( I to ground over-contact 2 of relay ON(I When relay P2 (2) operates the following functionsv are performed:

(l) Theoperating groundzfor relayvP2(2). on conductor |00 is extended over contactmI of relay P2(2) to .the left side of the winding. of relay PM2), relay P3(2) not being able tooperate because the right side of its Winding. is shunted to ground over contact 4 .of relay PI (2) (2) Contact 3 of relay P2(2) is closed to partly establish a shnnting groundcircuit (which will be 10 completed over conductor I0'I when relay L( I) reoperates at the end of the pulse) for shuntreleasing-relay PI (2) when relay L( I) reoperates;

(3) Contact 4 of relay P2 (2) is closed to extend ground to the right side of the winding of relay P4(2), thereby to prevent the operation of relay PM2) when and if relay P3(2) operates during a third pulse; and,

(4) Contact 4 of relay P2(2) grounds a circuit for operating relay P2A(I) extending from ground, over contact 4 of relay P2(2), conductor 202, contact 0 of relay PZA( I to battery through the winding of relay P2A(I), whereupon relay P2A(I) operates and locks over its contact I to off-normal ground over contact 2 of relay ON(I Whenrelay'LU) reoperates at the end of the second pulse, relay PI(2) is shunt-released by ground, over contact 2 ofrelay L(I), conductor I01, contact 3 of relay P2(2), to the right side of relayPI (2). I

At the end of the digit, relay RA( I) releases as above described to operaterelay RAI (I) momentarily as'also described previously. During the interval of time inherently necessary for any relay to operate there will be ashort period of time When the back contacts 3 and 4 of relay RA(I) are closed and the back contacts 3 and 4 of relay RAI (I) are also closed, due to the inherent operating time of relay RAI (I). During this interval. the digit 2 which has been counted by the counting chain of Fig. 2 must be steered to and registered in the A digit register relays A0(4) to A'I(4). .As will be appreciated, the digit value as counted is represented by one operated relay, such as `relay P2(2), out of tenrsuch relays; whereas, the digit registers off-Fig. 4 `are arranged to register digits on a two-out-of-ve code basis,- which code is illustrated by the table below, taking the A digit register as an example:

From an inspection of Fig. 4 it will be appreciated that the relays A0(4) to H0(4) can -be operated-.over conductor 400, relays AI (4) to HI(4) over conductor 40 I, relays suchas A2 (4) over conductor 402, relay A4(4) over conductorv 404, andr relay A101) `over conductor 40'I. These five conductors are connected to contacts of the counting relays such that upon the operation of one of such relays, say relay P2 (2) only two conductors of the ve will be arranged to have battery applied thereto as will be explained. Needless to say the two conductors energized will conform to the above code according to the digit represented by the counting relay operated. Battery is supplied over contact 5 of relay PZA( I contact 3 of relay RAI (I), contact 3 of relayA RA(I conductor |08, contacts 5 and 0 of relay P2(2) to conductors 400 and 402. Battery on conductors 400 and 402 is extended to the right sides of all relays A0 (4) to Ht(4) and A2(4) to H2M). At the same time ground is supplied over contact 4 of relay RA( I contact 4 of relay RAMI), conductor |00, contact 4 oi the A digit steering relay AS(3), conductor 30I to the -left sides of all of theA digit register relays A0(4) to A'I(4). Thus the only register relays of FigaV which are supplied by both solid groundl and solidv battery are relays AUM) and A2(4) These relays thereupon operate to register the first digit, exclusive of a 1 or 11 prefix, the current through these relays being referred to as the operate current. The increases of current through the relays AI (4), A4(4),AH4),B0(4) to HMG) andB2(4) to H201) are not suflicient to operate these others and such current is referred to as the non-operate current. y

When relay RAI(I) operates momentarily, as a result of the previously described charging of condenser C3(I), the above-described solid battery and solid ground supplies for the register relays of Fig. 4 are opened at contacts 3 and 4 of relay RA! (I). The current owing in the windings of relays A(4) and A2M) therefore drops to the previously described holding current value as limited by resistance R2I(4) in the ground supply over conductor |00 and by resistances R350!) and R33(4) in the battery supplies. This current is insuflicient to operate a relay of Fig. 4 but is suiiicient to hold operated any such relays, such as relays AQUI) and A2M) which have been operated.

Relay RAI(I), upon operating as previously described, releases relay P2(2) and reoperates and locks relay ST(2) preparatory to counting the next digit.

Relay RAI(I), upon operating, advances the steering circuit of Fig. 3 to permit the operation 1 of the B register relays according to the next digit. Relay BS(3) is operated in a circuit extending from ground, over contact I of relay RAI( I), contact 2 of relay PZA( I), conductor IIO, contact I of relay AS(3), winding of relay BS(3), to battery through resistance R42 3), and relay BS( 3) locks over its contact 2 to oir-normal ground on conductor 300. As was the abovedescribed case with the operating of counting relays of Fig. 2, the operation of relay BS(3) accomplishes the following functions:

(1) Prepares at its contact I a circuit for operating relay CS(3) at the end of the second digit registration, relay 08(3) not being able to operate at this time because of the ground shunt on the right side of its winding from contact 3 of relay AS(3);

(2) Prepares at its contact 3 acircuit for shunt-releasing relay AS(3) upon the release of relay RAMI);

(3) Grounds at its contact 4 the right side of the Winding of relay DS(3) to prevent the operation of relay DS(3) when and if relay CS(3) operates later; and,

(4) Prepares at its contact 5 a circuit for operating the B digit register relays BH4) to BH4) according to the pulse count registered in the counting relays of Fig. 2 at the end of the second digit.

Upon the eventual release of relay RAI (I), at the end of the transient period above described, relay AS(3) is shunt-released by ground, over contact 2 of relay RAI(I), contact 4 of relay P2A(I), conductor III, over contact 3 of relay BS(3) to the right side of the winding of relay AS(3). Relay AS(3), upon releasing, removes at its contact 3 the previous ground shunt on the right side of the Winding of relay CS(3), thereby enabling relay 08(3) to operate over contact I of relay BS( 3) at the end of the second digit. Relay AS(3), upon releasing, opens, at its contact 4, Athe circuit including conductor 30| to prevent any undesired effects upon relaysl A0(4) to AH4) upon subsequent grounding of conductor |09 for registering purposes.

l2 The A digit, assumed to be 2, has now been registered in relays A0(4) and A2(4), the digitsteering circuit of Fig. 3 has been advanced preparatory to registering the second digit, the pulse counting circuit of Fig. 2 has been restored to normal, and the interdigital timing relay RAG) and auxiliary relay RAI (I) have been released4 so that the entire circuit is prepared toreceive, count, steer, and register the second digit.

Counting, steering and registering the second digit Let it be assumed that the second digit is composed of three pulses. In the manner described above regarding the rst digit of two impulses, relay L( I) will release and reoperate in response to each pulse.

Upon the release of relay L(I), responsive to the open loop period of the first pulse, relay RA(I reoperated as above described thereby opening the operating circuits for the register relays of Fig. 4 and discharging condenser C3( I). The first release of relay L( I) operates and locks operated relay PI(2) as above described. Upon the reoperation of relay L(I), at the end of the rst pulse, relay ST(2) is shunt-released.

Upon the release of relay L(I), responsive to the open loop period of the second pulse, relay P2(2) is operated and locked, the operated relay PI (2) preventing relay P3(2) from also operating as above described. At the end of the second pulse, when relay L(I) reoperates, relay PI(2) is shunt-released thereby conditioning relay P3(2) for operation during the third pulse,y if any.

When relay L( I) release during the third pulse. relay P3(2) is operated in a circuit extending from ground, over contact 3 of relay ON(I), armature of relay L(I), contact 4 of relay L(I), contact 4 of relay SRU), conductor IUS, contact I of relay P2(2), winding of relay P3 (2) to battery through resistance R3(2). Relay P3(2) operates and locks over its contact 2 to off-normal ground on conductor 20|. Relay P4(2) cannot operate at this time due to the ground shunt on the right side of its winding from contact 4 of relay P2(2). Relay P3(2), upon operating, applies ground over its contact 4 to the right side of the winding of relay P5(2) to prevent the operation of the latter should relay P4(2) be 0perated in response to a fourth pulse. Relay P3(2), upon operating, also prepares at its contact 3 a shunt circuit for shunt-releasing relay P2 (2) upon the reoperation of relay L(I) at the end of the third pulse.

When relay L( I) reoperate's at the end of the third pulse, relay P2( 2) is shunt-released. When relay L( I) remains operated for a length of time which indicates an interdigital pause, relay RA( I) releases as above described.

Upon the release of relay RAM), and prior to the momentary operation of relay RAI (I), ground is applied over contact 4 of relay RAM), contact 4 of relay RAI (I), conductor |09, contact 5 of relay BS(3), conductor 302, to the left sides of relays BtUl) to BH4), and battery is applied over contact 5 of relay P2A(I), contact 3 of relay RA! (I), contact 3 of relay RA( I conductor Hi8, contacts 5 and 6 of relay P3( 2), conductors 45! and 432, to the right sides of relays AIM.) to HHB) and A203) to H2M). As previously explained, all of the relays BEM) to BH4) will carry increased current due to the solid ground applied to the left sides of their1 windings over conductor 332 and all of the relays AHF.) to HIM) and A2M) to H205) will carry increased current due increases, thereby increasing the current iiowing therethrough to the "operate yalue, whereupon relays BI (4) and 13?(4) operate. -The remaining "relays, such as BIl(4)-,'B4(4), B'|(4) AI (4), CI (4) to HI (4), and 02(4) Vto H2M), carryl increases of current only of the'non-operate-yalue and will not operate. Relay A2 (4) is already operated responsive to the registration of the rst digit 2, and Will remain operated.

-As soon asr relay RAI (I) operates momentarily,

` relay'P3(2) is released and relay S'VI(2 "is reoperated and locked as before 'to return the countingchain of Fig 2 to normal preparatory to registering the third digit. v l Relay RAMI), upon operating, removes' the solid ground and battery from the operating circuits of the register relays of Fig. d' whereupon ."relays A(4), AIM), BH4) and BENI)y 'remain foperated due tc the holding current flowing therethrough as limited by vresistances R(4), R34(4), R33(4), R2I (Il), and R2`2(4) Relay RAI(I), upon operating,` advances the steering relays of Fig. 3. Relay 05(3) operates in a circuit extending from ground, over contact I of relay RAI I contact 2 oi lrelay PZA( I conductor IIiJ, contact I of relay BS(3),'winding of relay CS(3) to battery through resistance R43 (3) Relay 05(3) locks over its contact 2 to off-normal ground onconductor 3&6. Relay"DS(3) vcannot operate at this timebecause the right side of its L inding is shunted to ground vover contacte of relay BS(3).

ARelay CS(3), upon operatingjperforms the fol- `lowing functions: (1) At its contact I prepares the4 operating cirlcuit for relay DS(3) to be completed at the end 4of the third digit;

' (2) At its contact 3 prepares the releasing f shunt for relayBS) to be completed when relay j "tofthe'solidlbattery applied rtothe right-sides of their windings over conductors 40I and 482.1' Only 'relays 'BI (4) and7B2(4) have' the beneiitfofboth f einer*thelnrsifrrcigit :has ceenizregistered; .relay 'CS 3 operates'iafterthe? second vdigithas-"been registered, etc.;-:andrelayfI-SG)'operates .to indicate that the seventii-'dig-i'thas been registered. iis-described by Dehn lor'i-Juscli,the' marker sei- -"zu1"e may be eiiecte'd underthe 'control 'of'such steering relays, for-instance iipontheope'ration 'oi-relay HSGB) "as an indication vthat a full' sevendigit numberhas been registered.

vlli the 'marker seiiuref start circuit should 'need 'to .be completed 'at an earlier-stage for 11X codes,

itis of course ebviousthat'theoperation of re- "lay HX( I) can closesuch a -circuit in cooperation with relay BS(3) thelatt'er relayope'ating-as an #indication that the Xdigit is'registered 'in' the 'binations of such start signal may beproduced as will be apparent from Dehn and Busch;`

' when the marker 'is seized, the information registered infFig, 4, along withother information of noparticular importance to the present invention, is transferred to register relays infthe '-marlrer vcircuit as 'indicated at the vbottom oi i T01-Marker. 25

TV/heh'the Seized 'marker-is' Satisfied, by` Suitable l" 'well-known checkcircuits,-that ithas received all of the necessary information from the originating register circuit, the oif -normal relay ON(I )fin the latter circuit-is released;thereby'rele'asing the entire originating register circuit t'normal.

- llt is to be understodthat theabove-described arrangements are merely illustrative 'ofl'the ap- "plication 'of vthe principles of the l'inyentionl ""Nu `merous- 'other arrangements may beidevise'd by tho'se skilled inv the f art* vwithout departing-from the spirit and scope`o`f`the` present invention. 4 *What is claimed is:

l'. 'In' asignaling system, a'cha'ino'f relayshaving windings,'a"rst' source ofl potential ofone 4( 1 magnitude; *nieansmfor "generating vrpulses' of 'another magnitude, 'a' pulsing 'conductorfor' ap- 'plyingpulses through`the` relay `windings`and l"through said rst source, a second'conductor at said othermagnitude of potentiaL'iirst contact means-closed bytheloperation of a'relayfto' lock 'said relay to said' second conductor, A'second con- "tact means closed bythe operation of said relay to connect the winding vofthe vnext succeeding relay to Said pulsing' conductor; third Contact means Upon the release of relay RAI (I), at the end of the transient period ci operation, relay BS(3) is shunt-released in a manner similar tolthat previously described in connection with the release of 'relay AS (3) All of the circuits arenow in condition." for receiving, counting, steering, 'and registering the Vnext digit. It is not considered necessary to rer -closed by the operation of said relay to 'prepare a rst shunt' across` the winding of thenext preceding relay, means to complete' saidrs't'shunt at the end of *theexistent pulse, Afourth contact 'mean'sfclose'd bythe i'operation of said relay to f prepare a second fshun't" across' thewinding "of the second 'succeedingrelay 'and means Vto complete said second shunt atthebeginning of the next peat the above description' for thelsucceeding digits, since the operation of the circuits is the same. Any number of digits may be counted, steered, and registered in this manner, provision for eight such digits (exclusive of a 1 or 1l prenx) having been shown.

Release of originating register pulse.

2.1 'In a 'signaling system," a chain' of .relays having windings, `a source of current',l means forgenerating pulses, a pulsingconductor for applying pulses through the relay windings and through said source, a grounded conductor, iirst contact means for each relay closed by the operation of said relay to lock said relay to said grounded conductor, a 'second contact means for each relay closed by the operation of said relay to connect the winding of the next succeeding relay to said pulsing conductor, third contact means for each relay closed by the operation of said relay to prepare a nrst shunt across the winding oi the next preceding relay, means to complete said rst shunt at the end of the existent pulse, fourth contact means for each relayl closed by the operation of said relay to prepare a second shunt pulses to the other sides of. the relay windings, a grounded conductor, nrst contact means for each relay closed by the operation of said relay to connect the other side of said relay windings to said grounded conductor, second contact means for each relay closed by the operation of said relay to connect the other side of the Winding of the next succeeding relay to said pulsing conductor, third contact means for each relay closed by the operation of said relay to apply ground to the -one side of the winding of the next preceding relay, means to apply ground to the other side of the winding of the next preceding relay at the end of the existent pulse to thereby shunt l release said next preceding relay, fourth con- 1 tact means for each relay closed by the operation -of said relay to apply ground to the one side of the winding of the second succeeding relay, and-means to apply ground to the other side of the winding of the second succeeding relay at the beginning of the next pulse.

4. In a signaling system, a chain of relays, each `relay having a winding and having only pairs of v-rnake contacts, a rst source of direct-current potential of one magnitude, resistances, each relay having one side ofv its Winding connected to Y said rst source through an individual one of said resistances, means for generating pulses of I vdirect-current potential of a different magnitude, `a pulsing conductor for applying said pulses to the other sides of said relay windings, a second conductor at said different potential, a first pair of contacts for each relay closed by the operation of said relay to connect the other side of said relay windings to said second conductor thereby -to lock said relayoperated, a second pair of contacts for each relay closed by the operation of said relay to connect the other side of the winding of the next succeeding relay to said pulsing conductor thereby to prepare for the operation of .said next succeeding relay by the next pulse, a

third pair of contacts for each relay closed by the operation of said relay to apply said diierent potential to the one side of the winding of the next preceding relay to prepare a rst shunt circ'uit across said next preceding rel'ay winding,

means to apply said different potential tothe other side of the next preceding relay winding at the end of the existent pulse therebyf'to shuntrelease said next preceding relay, a fourth pair of contacts for each relay closed by-theoperation of said relay to apply said diie'rent potential to the one side of the winding of the second succeeding relay to prepare a second shunt circuit across said second succeeding relay winding, and means to apply said different potential to the other side of said second succeeding relay winding at the beginning of the next pulse thereby to prevent the operation of second succeeding relay until said relay is released.

5. In a signaling system, a chain of relays, each relay having a winding and having only pairs of make contacts, a source of direct-current potential, resistances, each relay having one side of its winding connected to said source through an individual one of said resistances, means for generating pulses oi ground potential, a pulsing conductor for applying said pulses to the other sides of said relay windings, a grounded conductor, a rst pair of contacts for each relay closed by the operation of said relay to connect the other side of said relay winding to said=` grounded conductor thereby to lock said relay operated, a second pair of contacts for each relay closed by the operation of said relay to connect the other side of the winding of the next succeeding relay to said pulsing conductor thereby to prepare for the operation of said next succeeding relay by the next pulse, a third pair of contacts for each relay closed by the operation of said relay to apply ground to the one side of the winding of the next preceding relay to prepare a first ground shunt circuit across said next preceding relay winding, means to apply ground to the other side of the next preceding relay winding at the end of the existent pulsethereby to shunt-release said next preceding relay, a fourth pair of contacts for each relay closed by the operation of said relay to apply ground to the one side of the winding of the second succeeding relay to prepare a second ground shunt circuit across said second succeeding relay winding, and means to apply ground to the other side of said second succeeding relay winding at the beginning of the next pulse thereby to prevent the operation of said second succeeding relay until said relay is released.

FRANK K. LOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

